Three members of a gang accused of highway killings in the Russian capital were killed in a Moscow court after a shoot-out.

The defendants reportedly disarmed some court bailiffs at the Moscow Regional Court building on their August 1 trial date and got into a shoot-out.

Three of five defendants were killed and at least two court security officers and one other defendant were injured in the incident.

"I was attending a court hearing of an unrelated case," lawyer Sofia Rubasskaya told Rossia 24. "Then we heard shots -- approximately 25 shots were fired. On my way from the fourth to the third floor I saw a woman sitting on a bench. She was injured, her face was [covered] in blood. She was a bailiff."

Rubassakaya said the defendants, reported to be members of the GTA gang, stole a gun from a court guard that was escorting them.

The GTA (Grand Theft Auto) gang is alleged to have carried out a series of murders on Moscow highways in 2014 in which its members shot dead motorists after using caltrops to cause their cars to suffer flat tires.

The defendants in the high-profile case are mainly citizens of Central Asian countries.

The regional court was evacuated for about an hour before operations resumed in the building.

Russia's Investigative Committee has opened a criminal investigation into the shoot-out inside the court building.

Based on reporting by Reuters, RIA, Moskovsky Komsomolets, AP, Interfax, and TASS